The NEC PC-9821 computers output a very unusual resolution that most western monitors struggle with: 640 x 400 @ 24 kHz. I tried at least half a dozen monitors of all types and ages and none of them was able to display a picture at all (except an “out of range” message). Video scalers like the DVDO iScan VP50 Pro don’t recognize the signal either. Some sources claim that the cheap GBS-8220 converter is able to convert the signal – that is only partially true. You can see a stuttering picture that eventually becomes clear when you start the Windows 98 Desktop, but that doesn’t work in DOS.